cvs commit: src/sys/fs/unionfs union_vnops.c

[David Schultz]

On Sat, Jun 14, 2003, David Schultz wrote:
> das         2003/06/14 16:56:27 PDT
> 
>   FreeBSD src repository
> 
>   Modified files:
>     sys/fs/unionfs       union_vnops.c 
>   Log:
>   If someone tries to mount a union filesystem with another unionfs as
>   the upper layer, fail gracefully instead of panicing.

By the way, to clarify, VOP_WHITEOUT with the LOOKUP flag is used
by unionfs itself to detect whether the top layer you're trying to
mount over supports whiteout entries.  In this case, cnp->cn_thread
is NULL, so this commit fixes a null pointer dereference in the case
where one unionfs asks another whether it supports whiteout entries.